As more people use internet-enabled mobile phones, like the iPhone, the demand for mobile-enabled websites grows. Everyone likes to have their own information in their own hands, all the time. Creating these different interfaces can be a lot of work, but Joe Hewitt changed that on the iPhone front. The iUI User Interface Library was spawned and has popped up all over the place since (most notably on Facebook). The library just requires some simple HTML to create a very slick interface that mimics the iPhone interface.
Where was Drupal in all this though? There are a number of solutions for mobile-enabled Drupal websites, but none of them worked so well with the iPhone. So, I hacked together a iUI Drupal Theme, stuck it on Rob Loach .Mobi, and was surprised with the result. Go ahead, try it out! Aside from a few little things, it worked perfectly on the iPhone. Still needs lots of work, though.
So, if you want an iPhone-enabled version of your Drupal website, all you have to do is install the iUI Drupal Theme, and then switch to the iUI theme when the user visits your mobile-enabled website. You could do that by either a small hack in settings.php, or one of the many modules out there that changes the theme based on the user agent or the domain. Enjoy!